Popular probiotics have few cons, experts say

Every year, half of all Americans take some kind of pill as insurance against their diets.

But recently, researchers have noticed a surprising trend: Use of some of the most popular supplements is waning, possibly because of recent reports questioning their benefits and raising awareness about risks. In a study by the independent research group ConsumerLab.com, calcium supplementation declined among women, from 58% in 2012 to 46% in 2013 . Vitamin C purchases were off by 4.2%. Even sales of fish oil — once the hottest supplement on the market — dropped, according to the report.

The one category where supplementation is actually growing? Probiotics, or live bacteria that work by "recolonizing the small intestine and crowding out disease-causing bacteria, thereby restoring balance to the intestinal flora," according to ConsumerLab.com. From 2012 to 2013, use of probiotics rose from 31% to 37% among regular supplement users.